
Philip Kaufman is not a prolific director, and like Terrance Malick, he tends to make diverse films that explore differing genres and tones. (Kaufman is rumored to be developing the script for Indiana Jones 5, so god help us we may recover from Jones 4 after all) His approach to this Invasion was to build on the 1956 original narrative and characters, add a bit to the alien back story, and use 70s effects to show more of the snatching process on screen. He also brought a masterstroke to the Snatchers mythology: the piercing scream that the aliens emit when they identify a human in their midsts. (Used to excellent effect here, but bested by Meg Tilly's scream in Abel Ferrara's 1993 remake-of-a-remake Body Snatchers)
Another Kaufman trick is to use background or incidental imagery to unsettled the audience. Each time I watch the film I pick up on a visual clue in the background that totally creeps me out. Often it's just a handful of extras standing with blank stares; in one instance there is a man looking through a clouded glass window, staring at the main characters and tracking their movements. They only last a second or two, but it definitely creates a sense of overwhelming conspiracy. I was reminded of the way that Polanski uses sound to unsettle the audience in Chinatown, and, more recently, the way that Scorsese plays with the language of film editing and continuity in Shutter Island. I am always impressed when a director goes to lengths to add another layer to the experience.
If you haven't seen the film, it's a no-brainer to rent it immediately. Hell, I would recommend all versions of this basic story, even the Nicole Kidman movie The Invasion, just to see how each writer/director interprets the material.